When re-imaging a Windows 2003 server you will be prompted to activate Windows. When I did this it would not allow me to connect to the internet and thus I had to do it by phone. When entering the key info over the phone with Microsoft’s automated response system and then inputting the activation code given to me from the phone it told me that it was an invalid key. After much trouble I found that when I chose the option to change my CD key and then input the same CD Key I was using on the phone I was able to finally activate it over the phone.